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Probabilistic Estimates of Design Load Factors for Wind-Sensitive Structures Using the "Peaks Over Threshold" Approach.


pdf icon Probabilistic Estimates of Design Load Factors for Wind-Sensitive Structures Using the "Peaks Over Threshold" Approach. (921 K)
Whalen, T. M.

NIST TN 1418; 30 p. April 1996.

Available from:

Government Printing Office

Keywords:

building technology; building codes; climatology; extreme value theory; hurricanes; load factors; structural engineering; structural reliability; threshold methods; wind (meteorology)

Abstract:

The "peaks over threshold" method is used to estimate ratios of wind-induced loads with various long mean recurrence intervals to loads with a 50-year mean recurrence interval. The results support the conclusion that the load factor value of 1.3 specified in the ASCE Standards 7-93 and 7-95 is adequate for extratropical storm regions. However, for hurricane-prone regions, the results imply that the standard value of the load factor (even after being augmented by an importance factor specified in the standards) leads to nominal ultimate wind loads with considerably shorter mean recurrence intervals than is the case for extratropical regions. This suggests that the 1.3 load factor value specified in the ASCE Standards 7-93 and 7-95 is inadequate for wind-sensitive structures in hurricane-prone regions.